Renewable cartridge-fuse



A. H. TRUMBULL AND T. A. BOTH.

RENEWABLE CARTRIDGE FUSL APPLICATION FILED JULY 27,1918.

1,334,572. Patented Mar. 23, 1920.

. INVENTORS TTORNEY UNITED sTATEs PATENT oEEioE.

ALEXANDER H. TRUMBULLPAND TONJ ES A. BOTH, 0F STRATFORD, CONN ECTICUT, ASSIGNORS T0 THE CONNECTICUT ELECTRIC MANUFACTURING COMPANY, A.

CORPORATION 0F CONNECTICUT.

RENEWABLE CARTRIDGEFUSE.

Specification of Letters Patent.

Patented Mar. 23, 1920.

Application led July 27, 1918. Serial No. 247,071.

To all whom t may concern.'

Be it .known that we, ALEXANDER H. TRUMBULL and ToNJEs A. BOTH, citizens of the United States, residing at Stratford, county of Fairfield, State of Connecticut, have invented an Improvement in Renewable Cartridge-Fuses, of which the following is a specification.

This invention relates to renewable cartridge fuses of both the ferrule and blade types, it being understood of course that fuses for 60 amperes and under are usually of the ferrule type and fuses for 100 amperes and upward of the blade type, and the.

invention has for its object to provide a safety fuse in which the cost of construction shall be reduced to the minimum, special objects in View being to prevent injury to a switch base through bursting of the body or blowing oif of a head in the event of a blow out, to prevent arcing, and to do away with all danger of the fusing of metallic connecting parts which has heretofore rendered 'many so called renewable fuses useless after Fig. 5 a perspective view of the fuse strip.

detached;

Fig. 6 a perspective view of-one end of a fuse of the ferrule type showing the parts disassembled;

Fig. 7 a longitudinal section of onel en of a fuse of the blade type;

Fig. 7 a a longitudinal sectionof the other end of the fuse, which has beenv given a quarter turn;

Fig. 8 an end elevation as seen from the right in Fig. 7 a;

Fig. 9 a longitudinal section of one end of another form of blade fuse;

Fig. 9a a longitudinal section of the other end of the fuse, which has been given a quarter turn;

Fig. 10 an end elevation as seen from the right in Fig. 9a; and Fig. 11 is a view, partly in elevation and partly in section, illustrating a modification applicable to either type of fuse.

20 denotes the insulating body which is ordinarily a fiber tube and is provided near its ends with anchorages for engagement by screws, in the present instance with insulating cross tubes 21, which may also be of liber and the ends of which extend through the body and are internally threaded. Y22 denotes the fuse strip which is provided with an indication 23 which shows the safety amperage of the fuse, and nearits ends with holes 24. In the form illustrated in Fig.

5 the fuse strip is widened between its ends,

a central longitudinal' piece is blanked out leaving an elongated opening 25, and*` one end of the lstrip is split longitudinally, the split intersecting the opening and hole 24, s0 as to ermit the parts to be separated in assembling, as will be more fully explained.

Recesses 26,'diametrically opposite to each other, are provided in the ends of the body to receive the respective ends'of the fuse strip, which after being seated in the recesses are bent over thel ends .of the body and against the outer sides thereof. These recesses locate the fuse. strip and prevent d-isplacement thereof. 27 -denotes relatively light insulating washers which close theends ofthe body and contact with the ends of the body andv the respective ends of. the fuse strip. 28 denotes the ferrules, which may or may not be end Ventilating and are preferably providedwith central bosses 29 which contact with the washers leaving gas chambers 30 between the washers and the heads of the' ferrules. In the event ofa blow out the edges of the relatively light washers will be lifted thereby away from the ends of the body and the gas will pass into the chambers and out through holes 31 in the heads of the ferrules. The insulating washers are retained in the vferrules by means of a plurality of lugs 32 which are struck inward l from the metal of the ferrulesand against which the washers rest, grooves 33 being n the lugs.

provided in the ends of the body toreceive In order that they ferrules may fit-the ends of the body closely and'still provide spacev for the fuse strip', the metal of one side of each ferrule is pressed outward to form an closely, we preferably blank out spring tongues 36 from the metal of the 'enlargements, leaving one end attached and the i other end and the sides free tol spring, and

1 pass one of the screws 35 through the free end ofeach tongue.

In assembling the cross tubes are first seated in the walls of the body and become a permanent part thereof. The split end of i' vthe fuse strip is separated and passed on opposite sides `of the cross tube at 'one end i lof the body, then through the body and on 'opposite sides of the other cross tube, the cross tubes now lying at the ends of the :elongated opening in the fuse strip. 'Ihe ends of the fuse strip are now placed in the recesses 26 on opposite sides of the ends of the body and then bent over the outer side i i' of the body. The ferrules with the, insulatofthe fuse strip if preferred.

however, shown an indication at the solidv ingI washers in place are then slipped over I the lends of the body and secured by screws 35. Indications may be'placed at both ends IVe. have,

; end only -of the strip, this end of the strip the invention as applied to the blade type of I being made long enough to extend below 40, 6

the rrule and thus show the indication clearly, as in Fig. 1. The split end of the fuse 'strip is preferably left only long enough to lie flush with the edge of the feru rule, as shown at the right in Fig. 4.

In Figs. 7 to 1l inclusive, We have shown fuses and have also illustrated variations in the details of construction. In Figs. 7, 7f1

and 8, we have illustrated a form in which solid blades 37 are used which are riveted to the heads of the ferrules.' The attaching ends of the blades are provided with shoulders 38 which rest against the outer sides of the ferrule heads. The ends of the blades are passed through slots in the heads of the ferrules which just receive them and are headed down upon the inner side. Projecting central bosses 40 are left on the ends of the blades which contact with the insulating washers and serve the same purpose asthe bosses 29 in the other form. In this form we have shown a fuse strip 41 provided near each end with an offset having an opening 42 to receive the corresponding cross tube. A singlelong screw 43, thread- In order tov insure that both sides of the ferrules will grip formed from metal tubing flattened to place the sides in parallelism but not in contact, the object being to leave a passage 45 between the sides of the iattened tube for the escape of gas through thev blade'itself from chamber 30, in the event of a blow out. The attaching ends of the blades are provided with shoulders 46 which rest against the outer sides of theferrule heads.l The ends of the blades are passed through slots in the heads of the ferrules which Just receive them, and the sides of each flattened tube are bent outward at right angles to the blade on the inner side of the ferrule head. Projecting central lugs or bosses 47 are left on the ends of the blades which contact with the insulating washers and serve the' same purpose as in the form last described, that is, they hold the central portions 'of the relatively light washers while permitting the edgesof the washers to be lifted in the event 0f a blow out, so that the gas will pass into the chamber and out through the passa e in the blade. The fuse strip 48 in this 'orm is simply a plain strip of the ordina-ry type shown as 'made narrowest at its midlength. The cross tubes are dispensed with in this form and the screws 49 by which the ferrules are retained in place engage internally threaded hubs 50 which are firmly seated in In Figgll we have illustrated the use of metal -crosstubes 51, in lieu of insulating tubes, for engagement by the ferrule attaching screws, said metallic tubes being seated in the walls of the body and being insulated by outer fiber-tubes 52 which extend across between the inner walls of the body but do not extend through the body.

Having thus described our invention, we

claim:

1. In a fuse of the character described,a body, at fuse strip bent over the ends of the body and against the outer sides thereof, end Ventilating ferrules covering the ends of the body, insulating washers in the ferrules, and central bosses on the ferrules contacting with the washers and leaving chambers between the washers and the heads ofl the ferrules, the edges of the washers being lifted by a blow out and permitting escape of gas. l

2. In a fuse of the character described, a body, -a fusestrip bent. over the ends of the body and against the outer sides thereof and having an end indication, end ventilating ferrules covering the ends of the body, the indication on the strip extending below the edge of one ferrule, insulating Washers fuse strip bent over the ends of the body.

and against the outer sides thereof, ferrules covering the ends of the body, said ferrules being provided with enlargements which rep ceive the st-rip and with spring tongues in the enlargements, and screws carrled by said tongues and engaging the corresponding anchorages.

it. In a fuse of the character described,

a body provided with screw anchorages, a

-fuse strip bent over the ends of the body and against the outer sides thereof, ferrules covering the ends of the body, said ferrules being provided with enlargements which receive-the strip and the enlargments being provided with spring tongues, and screws passing through the tongues and engaging the anchorages.

5. In` a fuse of the character described, a bod provided with cross tubes, a fuse strip ent over the ends of the body and against the outer sides thereof, ferrules covv ering .the ends of the body, saidferrules being provided with enlargements which receive the strip and the enlargements being provided with spring tongues, and screws passing through the tongues and engaging the cross tubes. o

6'. In a fuse of the character described,

a body provided with cross' tubes, a fuse stri bent over the ends of the body and against the outer sides thereof and having means for locating the strip with relation to the cross tubes, ferrules covering the ends ofthe body, said ferrules being provided with enlargements which receive' the strip and the enlargements being provided with spring tongues, and screws passing through the tongues and engaging the cross tubes.

7. In a fuse of the character described, a body provided with cross tubes, a fuse Stri bent over the ends of the body and against the outer sides thereof and having an elongated opening which receives the cross tubes, one end-of the fuse being split for convenience in assembling, ferrules covering the ends of the body, said ferrules being provided with enlargements which receive the stri and the enlargements being provided witli spring tongues, and screws passing` through the tongues and engaging the cross tubes.

8. In a fuse of the character described, a body, a. fuse strip bent over the ends of the body and against the outer sides thereof, end Ventilating ferrules covering the ends of the body, said ferrules being provided with enlargements to receive the strip and with internal lugs, insulating Washers which rest against the lugs, and central bosses with twhich the opposite sides of the washers conact.

9. In al fuse of the character described, a body provided with screw anchorages, a fuse strip bent over the ends of the body and against the outer sides thereof, end ventilating ferrules covering the ends of the body, said ferrules being provided with enlargements to receive the strips and with internal lugs, insulating washers which rest against the lugs, central bosses with Which the opposite sides of the Washers contact, and screws engaging the anchoragesto secure the ferrules to the body.

10. In a fuse of the character described, a body rovided with screw anchorages, a fuse strip bent over the ends of the body and against the outer sidesthereof, end ventilating ferrules covering the ends of the body, said ferrules being provided with enlargements to receive the strips, with interna-l lugs and with'spring tongues, insulat-v ing washers which rest against the lugs, central bosses with which the outer sides of the washers contact, and screws passing through the tongues and-engaging the anchorages. 1

11. In a fuse of the character described, a body provided with screw anchorages, a fuse strip bent over the ends of the body and against the sides thereof, end Ventilating ferrules covering the ends of the body, said ferrules being provided with enlargements which receive the strip and the enlargements being provided with tongues, insulating washers in the ferrules, central bosses with which thewashers contact leaving chambers between the washers and the' heads of the .ferrules, and screws passing through the tongues and engaging the anchora es.

1 In a lfuse'l of the character escribed, a body, a fuse strip bentl over the ends of4 the body and against the outer sides therelof, end `Ventilating ferrules covering the ends of' the body and having slots, blades having shoulders which rest against the ferrule heads,'. tl'ie ends of the blades passing through the slots and being headed down on the inner side leaving central bosses, and

insulating washers in the ferrules which, contact with the bosses.

13. In a fuseor` the character described,

14. A cartridge fuse ferrule having an enlargement to receive a fuse strip, and a b y a screw. y

16. In a fuse of the'character described,

a body, a fuse strip, ferrules at the ends of the body, tongues in the ferrules, and attaching screws engaging the tongues and ferrules 'and the body.

17. In a fuse of the character described, a body, a fuse strip, Ventilating ferrules on the ends of the body9 said ferrules being provided With central bosses, insulating Washers secured in the ferrules and engaging the bosses and leaving chambers between the Washers and the heads of the ferrules, and means for detachablyl securing the ferrules to the body.

In testimony whereof We afix oursignatures.

ALEXANDER H. TRUMBULL. TONJES A. BOTH. 

